How many elements are there
1 answer:
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Answer:
Explanation:
*Since the titration is between the strong acid HCl and the strong base Ca(OH)2, the pH at the equivalent point should be 7. On interpolation, we will obtain that 9.50mL and 9.82 mL of HCl is required to completely neutralized the given Ca(OH)2 solution.
*pH at the equivalence point =7
we know that pH + pOH = 14
Hence pOH= 14-7=7
pOH= -log(OH-)
The concentration of OH-= 10-pH= 1X10-7 M
One reason for the low solubility may be the higher reaction temperature, Another reason is the common ion effect.
The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:
Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:
Here, m is mass and M is molar mass.
Putting the values,
Now, in 1 mole of Cu there are thus, in 0.03923 mol, number of Cu atoms will be:
Thus, number of atoms of Cu will be.